Rising Treasury yields and AI spending scrutiny threaten US stocks in the second half of 2026 as the Nasdaq posts its worst day since April 2025.

The Nasdaq Composite fell 4.18% and the S&P 500 dropped 2.64% as AI skepticism grows. Bitcoin showed resilience with only a 1.6% decline amid the selloff.

Shares of technology companies fell as doubts about the artificial-intelligence boom lingered.